With the upcoming version 7.4 we've changed our build process in order to support more and newer network interface cards than the default Debian kernel.

As of 7.3, we've added support for:

Broadcom BCM5706/5708/5709/5716 (bnx2 driver)
Broadcom BCM57710/57711/57711E (bnx2x driver)
Intel 82563/6/7, 82571/2/3/4/7/8, and 82583 PCI-E family of controllers. (e1000e driver)
Intel 82575/6- or 82580-based gigabit network adapters/connections. (igb driver)
Intel 8254x-based PCI and PCI-X gigabit network adapters/connections (e1000 driver)

If there are additional cards you'd like us to add, please send an email to support@untangle.com with the subject of "NIC Support Request" following information:

1.) The output of:
update-pciids ; lspci
2.) The make and model of the NIC
3.) and if possible a link to the source code for the linux network driver.

I will make updates to the HCL as appropriate.